Plastic waste management has received significant attention in recent decades due to the urgent global environmental crisis caused by plastic pollution. The versatile and durable nature of plastic has led to its widespread usage across various sectors. However, its nonbiodegradable nature contributes to unsustainable production practices, leading to extensive landfill usage and posing threats to marine ecosystems and the food chain. To address these environmental concerns, numerous challenges have been recently addressed through investigating alternative approaches for disposing of plastic waste, with the construction sector emerging as a promising option. Incorporating plastic waste materials into concrete not only offers economic benefits but also provides a valid alternative to conventional disposal methods. This paper presents the results of different experimental studies, some of them available in the literature and others new, discussing the feasibility of integrating plastic waste into concrete and its impact on mechanical properties. The influence of different sizes, natures, treatments, and percentages of plastic waste in the concrete mixtures is dealt with in order to provide further data for helping to understand the nonunivocal results in the literature, under the conviction that only further observations can help to understand the mechanics of concrete with plastic aggregates. The experimental investigation highlighted that one parameter that is better than others and can be considered to compare different experimental investigations is the variation in weight (due to the effective volume of plastics in the mix), determining a sort of increasing of porosity that degrades the mechanical characteristics. However, this seems inconsistent in some cases. Therefore, the need for further research is highlighted to refine production methods and optimize mix designs.
In recent years, the scientific community has focused its interest on innovative inorganic matrix composite materials, namely TRM (Textile Reinforced Mortar). This class of materials satisfies the need of retrofitting existing masonry buildings, by keeping the compatibility with the substrate. Different recent studies were addressed to improve the knowledge on their mechanical behaviour and some theoretical models were proposed for predicting the tensile response of TRM strips. However, this task is complex due to the heterogeneity of the constituent materials and the stress transfer mechanism developed between matrix and fabric through the interface in the cracked stage. This paper presents a state-of-the-art review on the existing constitutive models for the tensile behavior of TRM composites. Literature experimental results of tensile tests on TRM coupons are presented and compared with the most relevant analytical models proposed until now. Finally, a new experimental study is presented and its results are used to further verify the reliability of the literature expressions.
Historical masonry structures often suffer gradual deterioration that in many cases can compromise the safety levels and the operating conditions of the buildings. In this context, Structural Health Monitoring (SHM) is an effective tool for the prediction of the structural behaviour and the state of conservation of buildings. Although many monitoring systems have recently been proposed, there is a lack of practical application of low-cost systems. This paper presents an experimental study based on the use of two innovative stress sensors—capacitive stress sensor and ceramic stress sensor—for the monitoring of existing masonry elements. In order to reproduce the actual conditions of onsite masonry, sensors are post-installed in the mortar joints of two series of pre-stressed specimens made of calcarenite stone masonry and clay brick masonry. The best practice of post-installation of the two sensors is investigated. The reliability of the proposed sensors is evaluated through comparison with data recorded from classical measurement devices.
1 January 2022 in Construction and Building Materials
The modeling of the mechanical behavior of Fabric Reinforced Cementitious Matrix (FRCM) composites is a difficult task due to the complex mechanisms established at the fibre-matrix and composite-support interface level. Recently, several modeling approaches have been proposed to simulate the mechanical response of FRCM strengthening systems, however a simple and reliable procedure is still missing. In this paper, two simplified numerical models are proposed to simulate the tensile and shear bond behavior of FRCM composites. Both models take advantage of truss and non-linear spring elements to simulate the material components and the interface. The proposed approach enables us to deduce the global mechanical response in terms of stress-strain or stress-slip relations. The accuracy of the proposed models is validated against the experimental benchmarks available in the literature.
25 March 2025 in Bulletin of Earthquake Engineering
The vulnerability of coastal buildings to tsunami events has garnered increasing attention in the last decades due to the severe impacts of recent disasters. Numerous challenges have been addressed to develop valuable methodologies to estimate the probability of damage to structures and infrastructures and to formulate effective strategies to mitigate potential damages and losses. However, a comprehensive predictive framework for constructing damage probability models applicable across different structural types and tsunami scenarios, while also accounting for the potential impact of previous earthquake damage, is still missing. In the present study, a double-stage approach for investigating the vulnerability of masonry buildings under sequential earthquake-tsunami events is proposed and discussed. Monte Carlo simulations are performed, analyzing the response of different building classes, characterized by different numbers of storeys. The random generation of the involved and basic parameters characterizing structures and loads have been followed by time-history dynamic analyses for seismic actions and push-over analyses for tsunami loading. The results provide valuable insights for refining multi-risk evaluations, highlighting the impact of earthquake-induced damage on tsunami vulnerability compared with studies that neglect seismic effects. In the paper, the influence of previous random seismic action on tsunami loading vulnerability was obtained and translated into a new type of fragility curve for the earthquake-tsunami interaction. Meanwhile, the important effect of building height on tsunami vulnerability is stressed along with the influence of vertical loads and seismic intensity, expressed in terms of Peak Ground Acceleration (PGA). Comparative analyses were conducted to assess the effectiveness of the proposed methodology for constructing analytical fragility curves, evidencing the reliability of the proposed approach.